This paper summarizes results from the first NASA Life Support Systems Analysis Workshop sponsored by the Office of Aeronautics and Space Technology on June 24-27, 1991, in Milwaukee, Wisconsin, and provides a brief overview of the second workshop held May 12-14, 1992. The objectives of the workshops were to: 1) encourage communication in life support systems analysis among NASA, the aerospace industry, universities, and the chemical processing industry; 2) provide access and exposure to current NASA life support systems analysis efforts; 3) establish and provide results of the workshop sessions to NASA and the participants regarding future activities and directions for the development of life support systems analysis capabilities. The participants included representatives from NASA Headquarters and field centers, major aerospace companies, aerospace R&D and manufacturing companies, chemical processing companies, and universities. Key personnel in the fields of life support and chemical systems analysis gave presentations. Real-time computer demonstrations provided exposure to systems analysis models currently developed and available from NASA and other sources.In the 1991 workshop, five working groups were formed to apply the specialized talents and experiences of workshop attendees to discussions of these specific systems analysis development areas: (1) Steady State and Dynamics Systems Analysis, (2) Modeling Validation and Scale-up, (3) Evaluation Criteria, (4) Biological Systems Analysis, and (5) Systems Integration. Each working group articulated key development issues relating to systems analysis, an assessment of the current state-of-the-art, and potential recommendations for pursuit of those issues. The first day was devoted to defining the key issues and characterizing the state-of-the-art or the status of current developments. The second day continued with development of recommendations for each of the key issues identified. Working group leaders presented reports on the third day.